Abstract: The effect of (NaPO3)6 on the flotation performance of magnetite, camsellite and serpentine was investigated through the testings of purity, grain size and surface characteristics of single-block camsellite and its floatation experiments. The results showed that in the oleic acid system the (NaPO3)6 concentration is a critical point, i.e., the (NaPO3)6 suppression effect on magnetite is effective or ineffective if the concentration is lower or higher than 0.25 × 10^-4 mol/L, respectively, while in the lauryl amine system the suppression effect is unobvious or obvious if the concentration is lower or higher than 0.8 × 10^-4 mol/L, respectively. As to the camsellite, (NaPO3)6 is suppressible to it in oleic acid system but insuppressible in laural amine system. And (NaPO3)6 has no obvious effect on the floatability of serpentine in either oleic acid or lauryl amine systems. Moreover, the suppression effects of starch and Ca²⁺ on camsellite are discussed.